Shaft seal device



J. VON BRETHORST Feb. 18, 1941;

SHAFT SEAL DEVICE Filed Dec. 19, 1938 INVENTOR. BY JOERGEN VONBRETHORSTl ATTORNEX MM, g

the sealin point.

Patenkd Fears, 1941 UNITED STATES PATENT OFFICE.

' I 2,232,039 sum SEAL DEVICE Joergen Von Brethorst, Oakland, Calif.

Application December 19,1938, Serial No. 246,633

4 Claims. (01. 286-7) The invention relates to a. means for providing aliquid-sealing dam between a rotary shaft and. an enclosing sleeve forpreventing the passage of liquid in the sleeve along the shaft throughAn object of the invention is to provide a sealing ring assemblywhich isarranged for its pro vision and operative installation as a unit.

Another object is to provide an improved sealing ring which radiallygrips a shaft in its bore while providing a seal axially thereof at itsrim portion. 1

A further object is to providea sealing ring' unit which provides'ameans for securing it against rotation with respect to the sleeve withwhich it is coactive.

The invention. possesses other objects and features of advantage, someof which, with the foregoing, will beset forth or be apparent in'thefollowing description of a typical embodiment thereof, and in theaccompanying drawing, in which, I Figure 1 is an elevation showing asealing ring embodying the invention operatively engaged between a.shaft and an enclosing sleeve, the sleeve being shown in longitudinalaxial section.

Figure 2 is a fragmentaryview showing the assembly of Figure 1, but withthe sealing ring also shown in axial section.

. groove therein for receiving the spring element.

For purposes of illustration, the unitary sealing ring assembly 9 of myinvention is disclosed in Figures 1 to 3 as being operatively installedfor'sealing the space between a rotary shaft H and a tubular sleeve l2enclosing the shaft with its cylindrical bore coaxial with the shaft. Anannular channel i3 of uniform cross-section is dcfined about the shaftii for use as a stuffing box to receive the sealing ring 9 of myinvention in such manner that different ring portions are forciblypressed against -the shaft periphery and the sides of the channel Hi tocross-seal or dam the sleeve space thereat. In the present instance, thechannel i3 is defined between a gland-ring l4 and a. bushing i5 closelyfitting the sleeve bore and encircling the shaft in mutually spacedrelation at opposite ends of a sleeve bore portion which defines thechannel bottom.

As shown, the sleeve bore is stepped at a shoul- 5 der l6 for receivingthe gland ring I against said shoulder, and a removable locking member lengages registering perforations in the sleeve and the bushing I5 forsecuring the bushing in fixed relation to the shoulder i6 and so to the1p operative gland ring IA. The sleeve bore portion which receives thebearing i5 is arranged to contain a lubricant or other liquid, and, thepresent sealing ring is designed to prevent the escape of the liquidthrough and beyond it. As indicated, 15

the sleeve l2 extends from a housing l8 which sealedl'y receives itwhile securing the locking vide a shaft bearing or function solely forproviding one side of the channel i3.

It will now be notedthat the sealing unit 9 25 comprises a washer member2| which is preferably formed of a piece of sole leather, though someother fibrous and homogeneous composition having substantially the sameflexibility and compressibility and resistance to liquid action as 30sole leather maybe utilized. The washer 2| is a right cylinder inoutline, has its bore arranged to closely receive the shaft II, and isprovided with aperipheral groove 22 of uniform rectangular cross-sectionwhich is equally spaced from its flat end faces. In practice, it hasbeen found best to cut the groove 22 in a fiat ring of leather wherebythe density of the washer material is not efiected in providing thegroove. The sealing unit is completed bythe installation of an helicalspring member 23 in the washer groove 22, said spring being operative toeffect certain compressive and distortion effects on the washer 2!, asis hereinafter brought out.

The conformation of the spring 23 before its installation in the washergroove 22 is disclosed in Figures 5 and 6. The spring 23 preferablycomprises. at least two full turns of spring wire which are normallyspaced axially of the spring and define a helix of uniform size having abore diameter slightly less than the diameter of the bottom of theperipheral washer groove 22. The free end portions 26 of the spring aretapered to provide flattened extremities having their planes transverseto the spring axis, the tapering pref-- 56 erably being effected fromthe outer faces of the spring ends whereby the installed spring mayprovide a uniform urge to axial expansion of the washer opposite thegroove 22. The spring portions 24 normally extend tangentially from thecylinder of the spring, and are preferably tempered, or otherwisehardened, whereby at least their outer corners 25 may be harder than thematerial of the sleeve I2.

It'will now be noted that when the spring 23 is mounted on a free washer2|, the latter is operative to circumferentially expand the spring whilethe spring reacts to contract the washer, bore and thicken the washeropposite the groove 22. When the assembled unit is installed in thechannel l3 and is mounted on the shaft II, the aforesaid springreactions with the washer are operative to sealedly engage the washerbore with the shaft while permitting the shaft rotation, and to sealedlypress the end faces of the washer against the gland ring l4 and theopposed end of the bushing Hi to complete the desired liquid sealbetween the shaft and sleeve. It will, of course, be understood that thenormal thickness of the washer 2| should be approximately equal to thewidth of the channel I3 to provide for the desired axial sealing withthe opposed gland ring and bushing end faces.

When the shaft I I rotates in the washer bore in frictionally sealedengagement therewith, it urges an undesirable rotation of the washerwith the shaft and with respect to the sleeve, and the relatively hardspring points 25 extending beyond the cylinder of the washer andresiliently bearing against the sleeve bore portion at the channel I3are arranged for operation to prevent such rotation of the sealing unitwith respect to the sleeve by reason of their oblique and slightlypenetrative engagement with the material of the sleeve bore. In thismanner, the sealing unit is arranged to be held against rotation withthe shaft in either possible direction of rotation of the latter, as isrequired for shafts or axles of vehicles,

for instance. Since the present sealing ring unit 9 is not utilized toprovide a seal peripherally thereof, the sleeve bore need -not beprovided with a finished surface at the sealing point. Also, the lengthof wire in the spring 23 is preferably such that the mounted springpresents the spring end points 25 in substantially the same axial lineof the cylinder bore, whereby to insure a full lateral seal by thewasher.

In view of the foregoing, it will be understood that the presenttwo-element sealing unit provides a radial seal at a rotary shaftengaged in its bore, an axial seal with the, sides of the sleeve channelor stufiing box I 3'which receives it, and a self -contained means whichis constantly operative to prevent a rotation of the unit with theshaft, whereby to accomplish the major objectives of the invention in aparticularly simple and effective manner. While I have described thefeatures and principles of operation of a structure which I now considerto represent a preferred embodiment of my invention, I desire to have itunderstood that the present showing is primarily illustrative, and thatsuch changes may be made, when desired, as fall within the scope of thefollowing claims.

1. In a sealing ring for a rotary shaft, a cylindric washer of flexibleand compressible mafrom, said shaft and sleeve being arranged for theirrelative rotation, means within the sleeve cooperative with-the sleevebore to define a channel of rectangular cr0ss-section facing the shaft,a' sealing washer of flexible and compressible material fittedly engagedin said channel to receive the shaft through its bore and provided withan annular peripheral groove-coaxial therewith, and an helical springhaving a sharpened extremity and disposed in said groove in coaxialrelation with the washer and constantly operative to con tract thewasher about the shaft in sealing engagement therewith while presentingthe point of said sharpened extremity thereof directly against thesleeve bore in the channel to secure the spring and washer againstrotation with re.- spect to the sleeve.

3. In combination with a cylindrical shaft and an enclosing sleevehaving a cylindrical bore coaxial with the shaft in spaced relationthereto, said shaft and sleeve being arranged for their relativerotation, means within the sleeve cooperative with the sleeve bore todefine an annular channel having between the sleeve and shaft, a sealingWasher of flexible and compressible material fittedly engaged in saidchannel to receive the shaft through its bore and provided with anannular peripheral groove of uni-. form cross-section, and an helicalspring having a plurality of turns disposed in said groove andconstantly operative to axially expand the washer opposite the groove inpositive sealing engagement with the channel sides while radiallycontracting the washer for the sealing engagement of its bore with theshaft, and means on the spring constantly coactive with the sleevetoprevent a rotary movement of the spring and washer with respect to thesleeve and comprising sharpened spring extremities resiliently andobliquely bearing against the sleeve bore at the bottom of the channel.

4. In a "sealing ring for a shaft, a cylindric washer of flexible andcompressible material, and a helical spring of cylindrical outlinehaving a plurality of turns engaged peripherally about the washer incoaxial relation with the washer and constantly operative to urge asealing contraction of the washer about a shaft which is rotativelyengaged through the washer bore and having an extremity sharpened andextending tangentially from the cylinder of its turns and of the washer.

JOERGEN VON BRETHORST.

